Thursday, 11 February 2016

This morning, the LIGO consortium announced that they had detected the gravitational wave signature of a pair of inspiralling black holes. Large ones, at that.

Check out the "chirp" signal of the inpiralling black holes as measured both in Louisiana and Washington. The right hand panel also shows the Washington signal superimposed (and flipped), which shows how synchronous they are.

You might ask, so what? We already have a lot of evidence that supports General Relativity on a wide range of scales. It isn't as if we were waiting to 'prove Einstein right' (as many of the news headlines would have you believe). In fact, it would have been more of an issue if we hadn't seen gravitational waves.

So, more than it being an unexpected discovery, I'm emotional because it highlights a few of my favourite things about science:

We make predictions for what we should see.

The theory of GR predicts that gravitational radiation should be generated under these extreme conditions -- two black holes orbiting each other and spiralling in towards each other in the final moments before they merge into a lower mass black hole. But more than just simple analytical equations, scientists (many of which are in the LIGO consortium) numerically solve the relativistic equations that govern these scenarios, using incredible supercomputing resources (big shout out to my local supercomputer, SciNet, here in Canada!) and simulate what these signals should look like. Seeing the data match these simulations took my breath away.

We persevere when the going gets tough.

Many of the scientists working spent years petitioning their respective national science foundations for money and painstakingly improving the detector efficiency, detection algorithms, methodology etc. - even in the face of non-detections! Pushing those sensitivity curves into regimes we'd expect to see a signal can be thankless work - and seeing today the joy on the faces of the men and women who have been working so hard was increadible!

My friends were teasing me about the author list taking up the first few pages of the papers today. But you know what, folks? That's what happens sometimes when you want to take on these incredible challenges. And true, collaborations aren't always that large, but a major part of science is that we work together. We check each other's results, we find bugs, we test, we push - we disagree strongly! And yet at the end of the day we all do this because we feel like we are pushing back the boundaries of our own, and the world's ignorance. And illuminating (be it optically or now GRAVITATIONALLY) the cosmos.